1/*
2 * Copyright (C) 2015 Yusuke Suzuki <utatane.tea@gmail.com>.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
14 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
15 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
17 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
18 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
19 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
20 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
21 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
22 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
23 * THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#pragma once
27
28#include <limits>
29#include <wtf/Vector.h>
30#include <wtf/text/StringHash.h>
31#include <wtf/text/WTFString.h>
32
33namespace JSC {
34
35class TemplateObjectDescriptorTable;
36
37class TemplateObjectDescriptor : public RefCounted<TemplateObjectDescriptor> {
38public:
39 typedef Vector<String, 4> StringVector;
40 typedef Vector<Optional<String>, 4> OptionalStringVector;
41
42 enum DeletedValueTag { DeletedValue };
43 TemplateObjectDescriptor(DeletedValueTag);
44 enum EmptyValueTag { EmptyValue };
45 TemplateObjectDescriptor(EmptyValueTag);
46
47 bool isDeletedValue() const { return m_rawStrings.isEmpty() && m_hash == std::numeric_limits<unsigned>::max(); }
48
49 bool isEmptyValue() const { return m_rawStrings.isEmpty() && !m_hash; }
50
51 unsigned hash() const { return m_hash; }
52
53 const StringVector& rawStrings() const { return m_rawStrings; }
54 const OptionalStringVector& cookedStrings() const { return m_cookedStrings; }
55
56 bool operator==(const TemplateObjectDescriptor& other) const { return m_hash == other.m_hash && m_rawStrings == other.m_rawStrings; }
57 bool operator!=(const TemplateObjectDescriptor& other) const { return m_hash != other.m_hash || m_rawStrings != other.m_rawStrings; }
58
59 struct Hasher {
60 static unsigned hash(const TemplateObjectDescriptor& key) { return key.hash(); }
61 static bool equal(const TemplateObjectDescriptor& a, const TemplateObjectDescriptor& b) { return a == b; }
62 static const bool safeToCompareToEmptyOrDeleted = false;
63 };
64
65 static unsigned calculateHash(const StringVector& rawStrings);
66 ~TemplateObjectDescriptor();
67
68 static Ref<TemplateObjectDescriptor> create(StringVector&& rawStrings, OptionalStringVector&& cookedStrings)
69 {
70 return adoptRef(*new TemplateObjectDescriptor(WTFMove(rawStrings), WTFMove(cookedStrings)));
71 }
72
73private:
74 TemplateObjectDescriptor(StringVector&& rawStrings, OptionalStringVector&& cookedStrings);
75
76 StringVector m_rawStrings;
77 OptionalStringVector m_cookedStrings;
78 unsigned m_hash { 0 };
79};
80
81inline TemplateObjectDescriptor::TemplateObjectDescriptor(StringVector&& rawStrings, OptionalStringVector&& cookedStrings)
82 : m_rawStrings(WTFMove(rawStrings))
83 , m_cookedStrings(WTFMove(cookedStrings))
84 , m_hash(calculateHash(m_rawStrings))
85{
86}
87
88inline TemplateObjectDescriptor::TemplateObjectDescriptor(DeletedValueTag)
89 : m_hash(std::numeric_limits<unsigned>::max())
90{
91}
92
93inline TemplateObjectDescriptor::TemplateObjectDescriptor(EmptyValueTag)
94 : m_hash(0)
95{
96}
97
98inline unsigned TemplateObjectDescriptor::calculateHash(const StringVector& rawStrings)
99{
100 StringHasher hasher;
101 for (const String& string : rawStrings) {
102 if (string.is8Bit())
103 hasher.addCharacters(string.characters8(), string.length());
104 else
105 hasher.addCharacters(string.characters16(), string.length());
106 }
107 return hasher.hash();
108}
109
110} // namespace JSC
111
112namespace WTF {
113template<typename T> struct DefaultHash;
114
115template<> struct DefaultHash<JSC::TemplateObjectDescriptor> {
116 typedef JSC::TemplateObjectDescriptor::Hasher Hash;
117};
118
119template<> struct HashTraits<JSC::TemplateObjectDescriptor> : CustomHashTraits<JSC::TemplateObjectDescriptor> {
120};
121
122} // namespace WTF
123